Which audio codec does Skype use

Skype is giving away high quality audio codec 2021

Skype is licensing a high-quality audio codec in its latest VoIP (Voice over Internet Protocol) software free of charge to any developer or provider, the eBay subsidiary announced on Tuesday.

The codec, called Silk Can Deliver Sound Quality, captures the full sound of the human voice, according to Jonathan Christensen, General Manager for Audio and Video at Skype. This "super wideband" codec was introduced with the Skype 4.0 for Windows client announced last month. Christensen revealed the licensing program, now live, at the eComm conference in Burlingame, California.

The traditional telephone system uses a narrow band for speech from 400 Hz to 3,400 Hz, which cuts high and low frequencies. This allows speech to be transmitted on a standard 64 kb per second (Kbps) channel, but has disadvantages such as: B. the blurring of the difference between similar tones such as "f" and "s."

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VoIP can travel on a line fatter than 64 Kbps, so new codecs have been written to encode and decode speech with higher quality. With Silk, Skype can now reproduce the full range of typical speech frequencies that are audible to the human ear, from 50 Hz to 12,000 Hz, says Christensen. This will help callers identify different speakers on conference calls and make calls generally sound warmer, he said. At the same time, the new codec uses 50 percent less network bandwidth than the previous version of Skype.

The company is making the codec freely available to third party developers so that they can use it in any device or application, with or without Skype, Christensen said.

"We think this is one way the entire industry can take to a new standard of voice quality," said Christensen.

Despite the fact that Silk is "a very significant chunk" of Skype research and investment, the company is releasing development investments to make its popular peer-to-peer voice application work with a wide range of hardware and software clients, Christensen said . These include PC software, headsets, video conferencing systems, cordless telephones and cell phones. Skype is one of its partners Asustek Computer, Plantronics, Arm, LifeSize and HelloSoft. Plantronics will announce a headset with its own sound card on Wednesday that Christensen says can use the Silk codec.

Without a common codec, it would be difficult for Skype to run its software with this group of customers, Christensen said. It would be too complicated to agree on which codec codec to use, assuming the license requirements are different. Silk should be a simple solution for the partners.

Skype is also working to interoperate Silk with endpoints using SIP (Session Initiation Protocol), the emerging standard for signaling IP telephone networks. The company is talking to Digium, the distributor of the open source telephony platform Asterisk, and wants to do business with other partners, according to Christensen.

Silk runs on x86 chipsets for Windows, Macintosh and Linux systems and, according to Skype, the software was run on Arm and MIPS chip platforms.

In addition to Skype 4.0 for Windows, the high-quality codec is available on the Macintosh beta version 2.8; a final Mac version will be released in April. Linux is on a similar timeline, Christensen said.